A de facto standard is a custom or convention that is commonly used even though its use is not required.
De facto is a Latin phrase (literally "of fact"), here meaning "in practice but not necessarily ordained by … 展开

There are many examples of de facto consolidation of a standard by market forces and competition, in a two-sided market, after a dispute. Examples:
• Alternating … 展开

Examples of some well known de facto standards:
• The driver's seat side in a given country often starts as a user/industry preference, turning to a local tradition, then a traffic code.
• The 展开

• Appeal to tradition
• Dominant design
• Embrace, extend, and extinguish
• Format war
• Harmonization (standards) 展开